4F

[Guest guest]

,

It seems CMT 4F is DSS or this type of DSS is 4F. First,here's some

information I pulled off

http://www.neuro.wustl.edu/neuromuscular/time/hmsn.html

http://www.neuro.wustl.edu/neuromuscular/time/hmsn.html#cmt4f

CMT 4F

l Periaxin ; Chromosome 19q13.13-q13.2; Recessive

Gene mutations: Nonsense & Frameshift

Periaxin protein

Membrane protein

3 locations during development

Nuclear: Early

Adaxonal: Plasma membrane

Abaxonal: With myelin maturation; Schmidt-Lanterman incisure;

Paranodal

membranes

Function

Interacts with dystrophin-related protein 2 (DRP2): Via PDZ domains

Forms cluster at Schwann cell membrane with dystroglycan

? Participates in membrane-protein interactions that stabilize myelin

sheath

? Interacts with basal lamina surrounding Schwann cell

Isoforms contain PDZ motif & Nuclear localization signal

Epidemiology: Several ethnicities

Lebanese Shiite Muslim; North American Hispanic; Northern European;

Vietnamese

Clinical: Dejerine-Sottas

Onset: Early childhood; 4 weeks to < 7 years

Early development

Gestation & Delivery: Normal

Motor delay: Sitting age 12 to 18 months; Walking & Talking at 2

years

Gait: Wide based; Ataxic

Weakness

Severe

Distal legs at 9 to 10 years

Hands at 14 to 15 years

Progression: Slow

Sensory loss

More severe than other DSS or CMT

Ataxia (80%)

Pansensory

Arms & legs

Cranial nerves: Normal

Tendon reflexes: Absent

Skeletal: Mild kyphoscoliosis; Pes cavus (75%)

Clinical: CMT phenotype with early sensory loss

Genetics: C715X mutation, Homozygous

Onset: Childhood; Gait disorder

Clinical features

Scoliosis: Severe at 10 years

Weakness: Distal; Legs & Arms; Symmetric

Sensory loss: Severe; Distal; All modalities

Tendon reflexes: Absent

Progression: Very slow

Laboratory

Nerve conduction studies

Motor: Absent motor potentials or Severely slowed velocity

Sensory potentials

Usual: Absent

May be preserved in childhood, especially milder syndromes

Nerve pathology: Axonal loss (Severe); Onion bulbs;

Hypomyelination

And secondly, this site http://geneclinics.org/servlet/access?

prg=j & db=genetests & site=gt & id=8888891 & fcn=c & qry=53551 & res= & key=Z0ZGqqV

zi4B3P & show_flag=c

Then further on to this one that has info on 4A, 4E and 4F.

http://www.geneclinics.org/servlet/access?

db=geneclinics & id=8888891 & key=Z0ZGqqVzi4B3P & gry= & fcn=y & fw=1017 & filenam

e=/profiles/cmt4/index.html

Gretchen